Tumor-Induced Osteomalacia (TIO)

Understanding Tumor-Induced Osteomalacia (TIO)

Tumor-Induced Osteomalacia (TIO) is a rare disorder caused by small, slow-growing phosphaturic mesenchymal tumors (PMTs) that secrete excess fibroblast growth factor 23 (FGF23). This excess FGF23 leads to phosphate loss in the urine (hypophosphatemia), impaired activation of vitamin D, and subsequent weakening and softening of the bones—manifesting as osteomalacia in adults or rickets in children. These tumors are often difficult to locate and may occur in bones or soft tissues. If left untreated, TIO can result in fractures, persistent bone pain, and muscle weakness.

Common Signs and Symptoms of Tumor-Induced Osteomalacia:

• Bone Pain: Persistent or intermittent pain in the bones.
• Muscle Weakness: Generalized weakness and reduced stamina.
• Fractures: Increased susceptibility to fractures or stress fractures from minimal trauma.
• Skeletal Deformities: In children, this can present as rickets, with bone deformities.
• Fatigue: Overall tiredness and decreased energy levels.

This information is provided as a resource and is not intended to diagnose a condition or prescribe treatment. Please discuss any symptoms you may exhibit with your physician.